Analysis of related factors for adolescents’ intention to use alcohol in Korea

The harmful effects of alcohol consumption by adolescents have been increasingly emphasized. Thus, it is necessary to identify individual and environmental factors that encourage drinking. This study investigated factors associated with the sustainable use of alcohol (SUA) in adolescents who consume alcohol, and the possibility of future drinking (PFD) in non-drinking adolescents. Data from “The Adolescents Awareness Survey of Alcohol Encouraging Environment” by the Ministry of Health and Welfare and the Korea Health Promotion Institute (2017) were used. The survey was completed by 1,038 participant, selected through a proportional allocation extraction method, who were aged 13–18 years and lived in five cities with a population of over 1 million. The factors associated with SUA included gender (β = 0.634, p = 0.004), grade (8th β = 1.591, p<0.001, 9th β = 1.674, p<0.001, 10th β = 1.497, p = 0.001, 11th β = 1.041, p = 0.004, 12th β = 2.610, p<0.001), drinking alone (β = -2.147, p = 0.002), liquor commercial (β = 1.644, p<0.001), ease of alcohol purchase (β = 1.541, p = 0.025), parent’s recommendation for drinking (β = 1.084, p<0.001), not knowing the mother’s education level (β = -0.685, p = 0.045), positive expectancy of drinking (β = 0.141, p<0.001), number of pubs (β = 0.303, p = 0.002), internet game cafes (β = 0.456, p = 0.019), and karaokes (β = -0.098, p = 0.023) in the community. The factors associated with the PFD in non-drinkers were grade (8th β = 0.531, p = 0.024, 10th β = 0.717, p = 0.035, 12th β = 1.882, p = 0.001), liquor commercial (β = -1.355, p<0.001), parent’s recommendation for drinking (β = 0.783, p = 0.020), positive expectancy of drinking (β = 0.139, p<0.001), and relationship with the father (β = 0.072, p = 0.033). Multidimensional interventions, including those by individuals, parents, peers, and local communities, are needed to prevent SUA and the PFD in adolescents.


Introduction
Alcohol is one of the most prevalent substances used by adolescents, and adolescent drinking has been emerging as a serious public health problem worldwide [1,2]. Adolescents who started drinking before the age of 15 years showed a higher risk of alcohol dependence and abuse [3], alcohol-related car accidents [4], and other unintended injuries [5] during adulthood than those who started drinking at age 21 or older. Furthermore, since drugs such as tobacco and alcohol may act as gateways for illegal drugs, preventing alcohol consumption not only avoids or minimizes the harm caused by drinking alcohol but also delays the use of other drugs and prevents drug-related harm [6].
In previous studies, the factors that correlated to or influenced the drinking behavior of adolescents were divided into individual and environmental factors. Individual factors include socio-demographic variables such as type of school, grade level, age, gender, positive attitudes toward drinking, current smoking, knowledge about drinking and drugs, subjective stress level, depression, and positive drinking expectations that are aimed at improving sociability and sexual function [7,8].
The factors relating to the family and friends included parental drinking or poor relationships with parents [8,9], parents' recommendations of alcohol consumption [10], the number of friends who drank with, frequency of friends' drinking, and amount of alcohol that they consumed [7]. Parents' recommendation to drink in childhood displayed a particularly significant association with an increased likelihood of risky drinking later in adolescence [7].
It has been reported that non-drinkers are more likely to drink as their exposure to alcohol commercial advertising increases, as are current drinkers [11]. Liquor commercials and promotes to promote adolescents' positive impressions about alcohol use and encourages their intention to use alcohol. It further influences adolescents who have never drunk alcohol to have a positive attitude and intention to use alcohol through the effective messaging of advertising [12].
Environmental factors, including law and community ordinances, prohibit the sale and drinking of alcohol to adolescents under the age of 19 [13], however, these are not a deterrent to alcohol consumption. The higher the density of liquor stores in the community, the greater the alcohol-related harm [14]. The number of entertainment establishments and liquor stores also affects the current drinking rate of adolescents in the community [15].
As mentioned above, there are many studies on the factors that influence the current drinking behavior of adolescents. However, few studies have comprehensively compared individual and community environmental factors concurrently with adolescents who are not currently drinking but are likely to drink in the near future and adolescents who want to continue drinking without stopping in the near future.
Therefore, this study aimed to identify the influencing factors on the drinking intention of adolescents who currently drink and adolescents who do not currently drink but are likely to drink in the near future, and simultaneously compare and analyze individual and community environmental factors. Based on these results, we intended to sought evidence for reducing harmful factors that promote adolescent drinking, thereby helping to establish and implement effective adolescents drinking prevention policies.

Participants
This descriptive cross-sectional study aimed to identify the factors influencing the SUA of drinking adolescents and the PFD of non-drinking adolescents.
The data for this study were obtained from the Environmental Drinking Survey of Adolescent Drinking Promotion conducted by the Ministry of Health and Welfare and the Korea Health Promotion Institute in 2017. The participants for this survey were middle and high school students nationwide, aged 13 to 18 years, and included a total of 1,045 adolescents. Community environmental variables were whether the local governments had drinking ordinances in 2017 by searching the municipal regulations information system [17]. The data were derived from the statistics of businesses related to alcohol consumption by the administrative district units; These administrative districts are the locations of schools where participants attend. The number of supermarkets (Korean Standard Industrial Classification Code: 47121), convenience store chains (47122), general retail (47129), general entertainment bars (56211), dance bars (56212), pubs (56213), other bars (56219), internet game cafes (91222), and karaokes (91223) were analyzed.

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Variables (See Fig 1) such as gender, grade, the onset of drinking, ease of alcohol purchase, problematic drinking, subjective stress level, and parents' education level were based on the Korea Youth Risk Behavior (KYRBS) Web-based Survey (http://yhs.cdc.go.kr). The KYRBS was established in 2005 by the Centers for Disease Control and Prevention in Korea. The KYRBS is an ongoing national cross-sectional survey that assesses health-risk behaviors among middle-and high-school students and monitors progress toward achieving the national health objectives of Korea's National Health Plan 2020 and 2030. The framework of this study is shown in

Procedures
This survey was conducted from October 30, 2017, to December 14, 2017, targeting male and female adolescents aged 13-18 years who live in cities with a population of more than 1 million people. Based on the results of the 2016 Basic Education Statistics Survey, adolescents were selected according to the stratified system extraction method. The process for selecting the research participants was as follows: first, to select the schools to be surveyed, phylogenetic extraction was conducted in consideration of co-educational status and age for a balanced survey according to school type (middle school, general high school, special purpose high school, specialized high school, autonomous high school) and gender. In the selected schools, a survey was conducted targeting male and female students from classes with more than 30 students. Through this process, 1,045 students from 30 schools were surveyed.
Considering that the participants of the survey were adolescents, a professional interviewer conducted a face-to-face survey under the guidance of the school teacher only after obtaining consent from adolescents and their parents. The community data were obtained from the "Census of Establishment" conducted by Statistics Korea, which investigated all businesses with one or more employees.

Data analysis
All statistical analyses were carried out using SAS software (version 9.4), and results with p < .05 were interpreted as being statistically significant. Variables influencing SUA in drinking adolescents and PFD in non-drinking adolescents were classified into individual variables, family and peer variables, and environmental variables.
First, the chi-square test, t-test, and ANOVA tests were performed depending on the variable to verify the differences between alcohol drinking and non-drinking adolescents. A descriptive analysis of the community circumstances variables was performed.
The variables included were: (a) individual (gender, grade, subjective stress level, onset of drinking, problematic drinking, intention to use alcohol, positive expectancy of drinking, ease of alcohol purchase, desire to drink after watching liquor commercial, etc.), (b) peers (people I drank with lately), parents (close relationship with parents, parental education level, parental recommendation to drink, etc.), school (drinking experience at school events, recognized school drinking regulations for their experience), (d) community (whether or not there was a local drinking ordinance, and the number of bars including liquor stores etc.).
Linear regression was performed to explore variables affecting adolescents' intention to use alcohol to explore the relationship between the variables, and the dependent variables were intended to use alcohol, with continuous variables.
Finally, hierarchical multiple regression was performed considering individual, parents, peer, school, and local community environmental variables simultaneously. This analysis method was used to separate individual and community environmental factors and identify their relative impacts. This means that the relationship between the variables continues even if the analysis variables differ at the individual and community levels (the number of supermarkets, etc.) [19].

Ethical consideration
The questionnaires and agreements developed for the survey of the youth drinking-control environment were approved by the Bioethics Committee of the Korea Health Promotion Institute (IRB 1709-HR-010-01). At the time, the investigation was conducted with the written informed consent of adolescents and parents, and the investigation was conducted with the guidance of the school teacher only if the consent of adolescents and parents was obtained.
The research data was provided with a five-digit unique number given by the investigative agency, excluding the name of the person being investigated and the school name.

Characteristics of participants
A comparative analysis of drinking behavior among drinking and non-drinking adolescents is shown in Table 1.
The onset of drinking: There were 257 (40.92%) adolescents who started drinking before entering middle school (7th grade) and more than 13.0% had started by the 7th and 8th grades (p <0.001).
Desire to drink after watching liquor commercial: the idea of wanting to drink alcohol after encountering a liquor commercial was found in 393 drinkers (62.58%) and 333 non-drinkers (81.22%) (p <0.001).
Positive expectancy of drinking: The mean score for the positive expectancy of the effect from drinking was 22.05 (±7.47) points for drinkers and 17.84 (±8.24) for non-drinkers, showing higher expectancy of a positive drinking effect in the drinking group (p<0.001). When asked about sustainable drinking or intention to use alcohol, drinkers (mean score 11.56 [±3.91] and non-drinkers [mean score 8.31 [±3.04]) showed significant differences (p<0.001).

Environment that encourages drinking
The drinking ordinance of local governments, the number of supermarkets, convenience store chains, general retail stores, general entertainment bars, dance bars, other bars, pubs, internet game cafes, and karaoke in 35 Gu (local) of five cities in Korea are shown in Table 2.
The drinking ordinances of local governments include prohibitions on drinking in public places such as parks at any age; while 20 local governments have drinking-related ordinances, 15 local governments do not. Among the number of places selling alcohol, there were 15.44 (±12.28) other bars per square kilometer followed by general retail stores, convenience store chains, and karaokes. Adolescents' intention to use alcohol increased with the number of pubs (p = 0.033), other bars (p = 0.003), internet game cafes (p<0.001), and karaokes (p<0.001) in the local community.

Factors influencing SUA in drinking adolescents
The significant variables affecting SUA for drinkers were gender, grade, people who I drank with lately, desire to drink after being exposed to liquor commercials, parents' recommendations for drinking, mother's level of education, and positive expectancy of drinking. The power of this explanation is 38.0% (Table 3).

Factors influencing PFD in non-drinking adolescents
The variables that affect PFD of non-drinking adolescents were grade, desire to drink after watching liquor commercials, parents' recommendation for drinking, the degree of close relationship with fathers, and positive expectancy of drinking. The explanatory power was 30.3% (Table 3).

Factors associated with SUA by hierarchical multiple regression
The variables for the drinking adolescent's SUA were statistically significant with respect to gender, grade, people who I drank with lately, desire to drink after watching liquor commercial, ease of alcohol purchase, parental recommendation to drink, mother's level of education, positive expectancy of drinking, internet game cafes, pubs, and karaokes (Table 4).  SUA of male drinkers was 0.634 points higher than that of female drinkers (p = 0.004), and this increased as the grade went up. Compared to friends or classmates I drank with lately, drinking alone was 2.147 points lower (p = 0.002). The number of people who desire to drink after watching a liquor commercial increased by 1.644 points compared to "Middle" (p<0.001). SUA was 1.541 points higher among those who experienced it as "ease of alcohol purchase" compared to those who experienced it as "impossible to buy alcohol" (p = 0.025). Drinking increased by 1.084 points when adolescents recommended by parents (p<0.001) compared to when parents did not recommend that their children drink alcohol. Compared to cases in which the mother's educational level was higher than that of a college graduate, SUA of adolescents who responded "do not know" decreased by 0.685 points (p = 0.045). For drinkers, SUA increased by 0.141 points when positive expectancy of drinking increased by 1 (p<0.001). However, the rate of increase was not higher than that of non-drinking adolescents, which is believed to be due to the fact that they have already experienced the reality of expectancy of drinking. In the local community, when the number of pubs, increased by 1 per unit area of 1 km 2 , SUA increased by 0.303 points (p = 0.002), and when the number of internet game cafés increased by 1 per unit area of 1 km 2 , SUA increased by 0.456 (p = 0.019). On the other hand, SUA decreased by 0.098 points when the number of karaokes increased by 1 per unit area of 1 km 2 (p = 0.023).

Factors associated with PFD by hierarchical multiple regression
The variables associated with PFD of non-drinkers were grade, desire to drink after watching a liquor commercial, parents' recommendation for drinking, the close relationship with their father, and positive expectancy of drinking (Table 4).
PFD increased in the 8th grade (β = 0.531, p = 0.024), 10th grade (β = 0.717, p = 0.035), and 12th grade (β = 1.882, p = 0.001), when compared to the 7th grade among non-drinkers. This is believed to be because of 12th graders' (equivalent to high school seniors) subjective stress level during college entrance exams, and the students approaching the age of 19, which is a legally allowed drinking age in Korea. PFD was reduced by 1.355 points when adolescents responded to "Not having" compared to "Middle" in a desire to drink after watching a liquor commercial (p = 0.001). PFD increased by 0.783 points when adolescents responded to "Yes" of parental recommendations for drinking compared to "No" (p = 0.020). PFD increased by

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0.139 points, as positive expectancy of drinking increased by 1 (p<0.001). As their relationship with their fathers increased by 1, the PFD of adolescents increased by 0.072 points (p = 0.033).
On the other hand, the number of internet game cafes per 1 km 2 did not significantly affect the PFD of non-drinkers.

Discussion
This study identified the sustainable use of alcohol (SUA) in drinking adolescents and the possibility of future drinking (PFD) in non-drinking adolescents, living in large cities, and analyzed the factors affecting SUA and PFD using the adolescents' individual and community environmental variables. The analysis was performed using hierarchical multiple regression.
The results of the study show that the factors affecting SUA in drinking adolescents are gender, grade, people who I drank with lately, desire to drink after watching liquor commercials, ease of alcohol purchase, parents' recommendation for drinking, education level of the mother, positive expectancy of drinking at the individual level. These factors were found to influence the SUA. The associated community factors were the number of pubs, internet game cafés, and karaokes in the local community. The power of SUA explanation was 39.5%. The factors influencing PFD in non-drinking adolescents was grade, desire to drink after watching liquor commercials, parents' recommendation for drinking, positive expectancy of drinking, and the close relationship with their father. The example of not thinking about desire to drink after watching a liquor commercial was found to have a negative effect on PFD. There were no statistically significant variables for PFD associated with local community factors. The power of PFD explanation was 31.4%.
In this study, parents' recommendations for drinking were found to increase drinking intentions among both drinking and non-drinking adolescents, which is consistent with the results of previous studies that reported that the more parents drink, the more their children experience drinking alcohol [20]. In Korea, the experience of being encouraged to drink increases during family events [21]. This might be due to the social perception that adolescents can learn proper drinking etiquette from adults. It shows that a tolerant social atmosphere toward alcohol and parents' recommendations for drinking encouraged adolescents to drink, since it is interpreted as tacit acceptance of drinking, thus alleviating the guilt about ignoring the ban on drinking under the age of 19. This suggests that the culture of tolerance to drinking is deeply embedded in each family in Korea.
The parents' role is most important in preventing adolescent's drinking, and parental restrictions are necessary because strict parental control can lower the adolescent drinking rate [18]. Since adolescence is a period in which attitudes toward drinking are formed, it is necessary to change the false belief that parents' recommendations for drinking will have a positive effect on improving the relationship with children or on the establishment of good drinking attitudes through accurate education on drinking [22].
Among parent-child relationships, the relationship with the father was not significantly associated with alcohol consumption in drinking adolescents but was only found to be a weak influencing variable for PFD in non-drinking adolescents. This differs from the results of a previous study that reduced levels of alcohol use/misuse, delayed the onset of drinking, and such intentions when the parent-child relationship was good [23].
Liquor commercials appeared to be associated with the intention to use alcohol in both drinking and non-drinking adolescents. Drinking adolescents had increased SUA following being exposed to liquor commercials. However, the PFD for non-drinking adolescents decreased when they said they had no intention of drinking after watching liquor commercials. This result was partially consistent with another finding that the preference for alcohol advertising was high and the likelihood of drinking increased as exposure to advertising increased, with drinkers indicating that they drink more, and non-drinkers reporting a high intention to drink [15,24]. TV, mass media, print commercials, and internet social media, which can be easily accessed by adolescents, also targets related to alcohol consumption.
Positive emotional experiences, achievements, individuality, and camaraderie about drinking, observed through the media can influence the onset, duration, and frequency of drinking [25,26]. Therefore, continuous monitoring and policy interventions in various media are necessary [27].
SUA increased for drinking adolescents when positive expectancy of drinking increased. Positive expectancy of drinking is a strong predictor of SUA. In the case of drinking adolescents, it was consistent with previous studies that the higher the positive expectations about drinking, the higher the sustained drinking [28]. Positive expectancy of drinking has been reported to have a significant effect on alcohol consumption [28]. On the other hand, PFD increased for non-drinking adolescents when positive alcohol expectancy increased. In previous studies, non-drinking adolescents were found to be less likely to drink in the future [21], suggesting that positive expectancy of drinking does not affect the intention to drink in nondrinking adolescents.
Among the factors related to individual variables, adolescents' intentions to use alcohol decreased when considering drinking alone compared to drinking with peers. In adolescence, imitation plays an important role in the onset of drinking, and drinking peer influences continuous drinking [29]. Usually, drinking alone reduces simple negative emotions [30,31], and it is assumed that this will not lead to continuous drinking.
The number of pubs and internet game cafés was found to be a local community factor affecting SUA in drinking adolescents. Internet use amongst adolescents is positively related to drinking; the study is based on the evidence that exposure to alcohol through the Internet and social networking sites (SNS) increases, and the drinking rate increases through social online activities with friends [32]. The fact that there are many places for adolescents to meet and buy alcohol in the community can be interpreted as the provision of an atmosphere in the community that is tolerant of drinking. Internet use also leads to decreased cognitive and behavioral self-control, which increases problematic drinking behavior [33]. This study found that drinking environment in the community influenced adolescents' drinking intentions. In the case of drinking prevention policy, it is necessary to actively promote policies that lead to environmental control, such as the regulation of the number of pubs and places where alcohol is sold in the local community.
Current drinking prevention education for adolescents is formal and fragmentary, but there has been no increase in the prevalence of drinking among adolescents. However, in recent years, ease of alcohol purchase has been on the rise, and the experience rate of drinking prevention education has decreased significantly [34]. It will be necessary to develop a specific prevention drinking program for non-drinking adolescents, as well as active stopping drinking campaigns and individual counseling for drinking adolescents. Early drinking onset in adolescence is associated with an early drug abuse behavior that may lead to problematic drinking in adulthood, which also affects health behavior problems [35,36]. Therefore, if there is no solution to the current drinking behavior of drinking adolescents, it may become a risk factor for future social problems. It is thus necessary to effectively deliver messages, such as the 'principle of zero tolerance' and 'prohibition of drinking under the age of 19' to legal regulations for adolescents.

Conclusions
One of the goals of the adolescent drinking prevention policy is to delay the initiation of alcohol consumption by changing the legal drinking age. This is because the earlier the drinking age, the greater the risk of alcohol-related disability regarding adolescents' growth and development, and the higher the likelihood of substance abuse or addiction during adulthood. In this context, it is essential to prevent or reduce drinking among adolescents by identifying factors related to their drinking intentions and considering the possibility of drinking for nondrinkers who have not yet started drinking, especially adolescents who have experimented only once or twice out of curiosity.
This cross-sectional study aimed to examine the drinking behavior of adolescents. The study had some limitations; since this study had a cross-sectional design, it was not possible to prove the direction of the association. To prevent the possibility and sustainability of drinking of adolescent drinking in advance, it is important to control the influence of factors that promote drinking in the community and to prepare a specific and strong policy that can limit it.